[Show abstract][Hide abstract] ABSTRACT: Free electron LASer in Hamburg (FLASH) at DESY is a user facility with laser-like radiation source in the VUV and soft X-ray range. It is also a pilot facility for the future XFEL. A fast data acquisition system (DAQ) to support the accelerator operation and the user experiments was developed. The system collects data from hundreds of ADC channels in the range of 1 M up to 2 G samples per second. In addition it allows collecting images from digital video cameras. All the data is collected in a shared memory of a central multiprocessor computer. Several processes are used to calculate e.g., the orbit, energy or photon flux, or are used as feedback loops to improve the stability of the linac. A long time archiving of the collected data from the accelerator and from the FEL experiments on a 24 TB disk and finally on a tape is provided. The whole system is integrated in the DOOCS control system of FLASH. It is a novel approach to combine a fast DAQ system with a accelerator control system.
Full-text · Article · Mar 2008 · IEEE Transactions on Nuclear Science
[Show abstract][Hide abstract] ABSTRACT: For the VUV-FEL (Vacuum-Ultraviolet Free Electron Laser) at DESY a 1 GeV superconducting LINAC (1) is used and presently being commissioned. The control system of the LINAC consists of 900 fast and 500 slow data channels producing up to 100 MByte/s of data depending on the LINAC operation mode. To study, control and archive the machine status and performance, a data acquisition system (DAQ) has been developed which allows storing machine parameters together with user experiment data. The system will provide the ability to correlate easily the accelerator status with experimental data on a bunch-by-bunch basis. The paper gives an overview on the architecture of the DAQ system and describes its main components in more detail.
[Show abstract][Hide abstract] ABSTRACT: The Data Acquisition System at the Free-Electron-Laser Hamburg (FLASH) has evolved since its implementation in 2005 into a reliable and versatile system, used for accelerator operations and studies along with a multitude of different photon experiment users, recording about 14 TB in 2008 for experiments only. Recently the DAQ system has been successfully upgraded with new hardware to accommodate increasing demands of beam line experiments, upcoming R&D work at FLASH i.e. for the ILC, and to prepare for the upgrade of the FLASH facility this year. This paper describes the evolution of and experiences with the FLASH DAQ and highlights the key elements of its design to facilitate an expandable yet easily to duplicate system implementation.
[Show abstract][Hide abstract] ABSTRACT: The VUV-FEL (Vacuum-Ultraviolet Free-Electron Laser) at DESY started recently its operation. As part of the Distributed Object-Oriented Control System (DOOCS) a novel Data AcQuisition (DAQ) System has been developed for this complex facility. To provide full diagnostics of all electron bunches, a fast ADC-based acquisition is used for collecting data from more than 800 channels at sampling rates of 1 to 9 MHz. The system allows data transfer rates of up to 100 MBytes per second to a central server. On this server data from all front end sources is synchronized and used by high level feedback and calculation programs. The data is stored for off-line analysis on a disk cache and eventually written to a tape server. A data volume of up to 70 TBytes per year is expected. The system implements technologies borrowed from High-Energy Physics experiments and integrate them fully into the existing DOOCS control system architecture.